/*
 *  Copyright 2007-2008 by Matthias Buch-Kromann <mbk.isv@cbs.dk>.
 *  *
 *  This file is part of the Open-source Dependency Toolkit (OSDT),
 *  see http://code.google.com/p/open-source-dependency-toolkit.
 *  
 *  The OSDT is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as 
 *  published by the Free Software Foundation, either version 3 of 
 *  the License, or (at your option) any later version.
 * 
 *  The OSDT is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 * 
 *  You should have received a copy of the GNU Lesser General Public 
 *  License along with the OSDT in the files COPYING and COPYING.LESSER.
 *  If not, see http://www.gnu.org/licenses.
 */

package org.osdtsystem.functions;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.osdtsystem.graphs.GraphAccessor;


/**
 *
 * @author Matthias Buch-Kromann <mbk.isv@cbs.dk>
 */
public class FuncUnion<V> extends AbstractFunction<V> {
    List<Function<? extends V>> arguments;

    FuncUnion(Function<? extends V>... arguments) {
        super(arguments);
        this.arguments = Arrays.asList(arguments);
    }

    @Override
    public List<V> _functionValue(LocalFunction<?, ?> caller, FunctionContext context, GraphAccessor accessor) {
        // Compute union
        Set<V> union = new HashSet<V>();
        for (Function<? extends V> f : arguments)
            union.addAll(f.functionValue(caller, context, accessor));

        // Compute list
        List<V> list = new ArrayList<V>();
        list.addAll(union);
        return list;
    }

    @Override
    void toStringBuilder(FunctionStringBuilder builder) {
        builder.addSubfunctions(arguments);
    }
}
